Reproductive biology of two sympatric skates in the Southwest Atlantic: Psammobatis rudis Günther, 1870 and P. normani McEachran, 1983

MABRAGAÑA, E.; COUSSEAU, M. B.

JOURNAL OF FISH BIOLOGY

Año: 2004 vol. 65 p. 559 - 573

0022-1112

The total lengths (LT) at which 50% were mature of Psammobatis rudis and Psammobatis normani, in the south-west Atlantic were: P. rudis, 428mm for males and 414mm for females and P. normani, 443mm for males and 403mm for females. Clasper length in mature males was greater in P. normani than in P. rudis, whereas oviducal gland width was not different between species. Females of P. normani with egg cases were found in every month sampled, and in January, March, April and July in P. rudis, although insufficient samples were available to identify peak oviposition times. Geographic variation in size frequency and maturity were found. The effects of oceanographic conditions and fishing pressure are discussed. Size at 50% maturity in both species was >74% of the maximum LT, indicating late sexual maturity and low potential stock recovery rate.LT) at which 50% were mature of Psammobatis rudis and Psammobatis normani, in the south-west Atlantic were: P. rudis, 428mm for males and 414mm for females and P. normani, 443mm for males and 403mm for females. Clasper length in mature males was greater in P. normani than in P. rudis, whereas oviducal gland width was not different between species. Females of P. normani with egg cases were found in every month sampled, and in January, March, April and July in P. rudis, although insufficient samples were available to identify peak oviposition times. Geographic variation in size frequency and maturity were found. The effects of oceanographic conditions and fishing pressure are discussed. Size at 50% maturity in both species was >74% of the maximum LT, indicating late sexual maturity and low potential stock recovery rate., in the south-west Atlantic were: P. rudis, 428mm for males and 414mm for females and P. normani, 443mm for males and 403mm for females. Clasper length in mature males was greater in P. normani than in P. rudis, whereas oviducal gland width was not different between species. Females of P. normani with egg cases were found in every month sampled, and in January, March, April and July in P. rudis, although insufficient samples were available to identify peak oviposition times. Geographic variation in size frequency and maturity were found. The effects of oceanographic conditions and fishing pressure are discussed. Size at 50% maturity in both species was >74% of the maximum LT, indicating late sexual maturity and low potential stock recovery rate.P. normani, 443mm for males and 403mm for females. Clasper length in mature males was greater in P. normani than in P. rudis, whereas oviducal gland width was not different between species. Females of P. normani with egg cases were found in every month sampled, and in January, March, April and July in P. rudis, although insufficient samples were available to identify peak oviposition times. Geographic variation in size frequency and maturity were found. The effects of oceanographic conditions and fishing pressure are discussed. Size at 50% maturity in both species was >74% of the maximum LT, indicating late sexual maturity and low potential stock recovery rate.P. normani than in P. rudis, whereas oviducal gland width was not different between species. Females of P. normani with egg cases were found in every month sampled, and in January, March, April and July in P. rudis, although insufficient samples were available to identify peak oviposition times. Geographic variation in size frequency and maturity were found. The effects of oceanographic conditions and fishing pressure are discussed. Size at 50% maturity in both species was >74% of the maximum LT, indicating late sexual maturity and low potential stock recovery rate.P. normani with egg cases were found in every month sampled, and in January, March, April and July in P. rudis, although insufficient samples were available to identify peak oviposition times. Geographic variation in size frequency and maturity were found. The effects of oceanographic conditions and fishing pressure are discussed. Size at 50% maturity in both species was >74% of the maximum LT, indicating late sexual maturity and low potential stock recovery rate.P. rudis, although insufficient samples were available to identify peak oviposition times. Geographic variation in size frequency and maturity were found. The effects of oceanographic conditions and fishing pressure are discussed. Size at 50% maturity in both species was >74% of the maximum LT, indicating late sexual maturity and low potential stock recovery rate.% maturity in both species was >74% of the maximum LT, indicating late sexual maturity and low potential stock recovery rate.